ST. LOUIS — Thirty-eight years ago, the last time the Arizona Cardinals were 4-0, their home was St. Louis and they were known affectionately as the Big Red.

Nearly a quarter century since departing for the desert, they're on top of their game again.

The surprising Cardinals don't have one of the best offenses in the NFL, far from it actually. Throw out the big plays on defense and they're pretty much middle of the road there, too. Their games are going down to the wire, the last two ending in overtime and three of them decided by a total of nine points.

Not surprisingly, they're just a 1-point favorite to beat the St. Louis Rams. On Thursday night, the Cardinals will have a shot at being the first team to 5-0, two wins shy of the 7-0 start in 1974 by a team that featured Hall of Famers Dan Dierdorf, Roger Wehrli, Larry Wilson and Jackie Smith.

One of the advantages to all the close calls is there's no danger of overconfidence.

"Obviously, we're excited to be 4-0," coach Ken Whisenhunt said. "We've had four up and down games. We've had a lot of trauma in them, so there's been a lot of emotion extended.

"But just to be where we are, we're certainly pleased about that."

The Cardinals have had a knack for handling late-game pressure since midway through last year, when they rebounded from a 1-6 start and became the first NFL team to win four overtime games in a season. All eight of their wins last season were by a touchdown or less.

They're still in that mode, winning the 500th game in club history last week after forcing overtime on Kevin Kolb's TD pass to Andre Roberts with 22 seconds to go. The Dolphins gained 480 yards but scored just two touchdowns last week as Arizona won its seventh straight overtime game.

As coaches say all the time, it's a bottom line business.

"They are a hell of a team, they're really well-coached," Rams defensive end Chris Long said. "They're 4-0 and rightfully so, they've done things to win those games.

"It's going to be a great challenge for us. I really mean that."

There's good reason for those words of respect.

The series has been quite lopsided between the club that departed St. Louis in 1988 after big money squabbling thwarted plans for a new stadium, and the franchise that replaced them in 1995 after receiving a bounty of concessions. Among them is a lease that could allow to team to leave after the 2014 season if their domed stadium isn't deemed to be in "first tier status."

The Cardinals have won 10 of the last 11 since the second meeting in 2006, half of them by double digits, and have a franchise-best seven-game winning streak in St. Louis. Punt returns for touchdown by Patrick Peterson fueled both victories last season, one of them in overtime.

"I'm sorry that those guys are back up on the schedule again," Peterson said. "But if they give me an opportunity, I have to do my job."

The Rams (2-2) have made great strides under new coach Jeff Fisher, with every game up for grabs in the fourth quarter. The defense has been opportunistic with a league-leading eight interceptions, three of them last week capped by Brandon Fletcher's clinching pick with a minute to go that foiled the Seahawks' comeback bid.

The offense is developing despite severe injury woes on the line, with each member of the patchwork unit receiving a game ball last week after limiting the Seahawks to two sacks. Sam Bradford has had more time to establish chemistry with the deepest group of pass catchers he's had in his three NFL seasons. Cross midfield and they're in range for rookie kicker Greg Zuerlein, who's 12 for 12 and last week became the first kicker in NFL history to make field goals from 50-plus and 60 yards in a game.

If they can end the Cardinals' unbeaten run, they'll be 3-0 at home, where they're slowly regaining fan trust. The franchise was 15-65 the previous five seasons, the worst five-year streak in NFL history.

"Well yes, you establish rivalries, but I wouldn't imagine we have one based on past history over the last four or five years," Fisher said. "We haven't had much a rivalry with anybody, so we have to work toward that, and that comes from having competitive, great games and close games and those kind of things."

Both teams have a short work week. It'll be the Rams' first prime-time game at home since playing Pittsburgh in 2007, and just the eighth Thursday night game in club history.

Arizona is playing on Thursday night for the first time since 2008.

"It's an easy adjustment for me. I'm 22 years old, so I can bounce back fairly quicker than the other guys around here in the locker room," Peterson said.

If the Rams prevail, they'll have a winning record for the first time since 2006, when they began 4-1 before losing five in a row. It's a run of futility running back Steven Jackson, who's been with St. Louis since 2004 and has yet to play on a team that finished above .500.

"I've only been a Ram, so it would feel good," Jackson said. "I hope to retire a Ram, so I hope to have a lot more of those."